Jonny2448

I know it is a Si but it si a 2000 so I am going to post it here. I am sure many have asked but I can't find the exact thing I am looking for. It is a B16a2 engine and The top hose is hot to where I can barely touch it and the bottom is super cool at the base where the bottom hose meets the radiator and it get a lil warmer toward the engine but prob just because the engine is there. So to me that says that it is the thermostat and I don't want to pay over 100$ to have someone else do it for me. I have seen some pics but some say the top tube and some say the bottom tube.


Basic Questions are....

Is it the top(Hot) hose or bottom (Too cold)?
Do I HAVE to drain the radiator?


Thanks a ton

BlueEM2

iTrader: (1)

Your top hose is supposed to be hot as it is a return from the engine. Your bottom hose is supposed to be cold as the coolant is cooled through the radiator and sent back into the engine. You don't want hot water being sent back into the engine because that is when you start overheating and destroying parts. Is the coolant circulating? Is the car overheating? It's in the title but I wanna confirm your temperature gauge is going past half.

I also moved this thread to a more appropriate place.

Jonny2448

Thanks. Well I just squeezed the top and bottom hose and i heard the swishing of water. When I squeezed the top to and release as a released it i heard a click so maybe the thermostat is working? Yes it is over halfway. usually it stays 2 dashes below the halfway and it went all the way to the top when I was it. The 2nd half of my drive back home after cooling it all the way down i ran the heater and turned it off at stoplights and was real light on the gas and it just barely above half but still above avg. It was cooling down and the sun was setting. It was a 4 mile drive. It has just under 70,000 miles. Hasn't had any major repairs or services since I had it.. about 20,000 I know thats bad. I was going to take it in today cause I got paid but well **** happens.

gearbox

iTrader: (95)

on a normal day around 75F outside, both top and bottom hoses should be very hot. if the bottom is cold or warm, not good. means your thermostat isnt opening fully or at all. its fairly easy to replace yourself, just drain a small amount of coolant from the radiator, unbolt the thermostat housing, swap the parts the same way you took the old one out and use a new gasket and honda thermo, then bolt back and add the coolant. you might need to bleed the air a bit if you hear bubbling noises but for such a small amount of coolant being drained, i doubt it. do not use aftermarket parts! honda only.

now if this was in a cold winter, then yeah the bottom hose will be less hot but still should be warm.

Jonny2448

Ok so where is the thermostat located? The top or bottom hose? I seem to get 50/50 answers

BlueEM2

iTrader: (1)

My bottom hose takes a long time to get warm (car has to reach optimal running temperate) and then a lil longer. If you squeezed the hose and heard a pop that's not how a thermo is supposed to function. Just change it, see if it helps. It however does not get nearly as hot as the top one. I never have troubles holding it. By cold I mean cooler than the top I guess haha.

Jonny2448

Ok http://www.hondacivicrepairs.com/vie...at-housing.JPG Thats the closest pic I can find that looks like where my bottom hose goes into.. is that the thermostat in there?

Jonny2448

I am going to go with the top tube. going to go a new hose and a drain pan.. have to walk there ...

gearbox

iTrader: (95)

i cant remember where they are on your car. sometimes its in the front, sometimes back of the engine.

BlueEM2 sounds like you have a weak thermo to me. in the summer the car should be warmed up fast (5 mins to the operating temp line) and after 10-15 mins the thermo should be fully open and both upper and lower hoses should be too hot to touch (shouldnt be able to feel differences between them, they should both be too hot). our engines are small so a weak thermostat is harder to notice, but eventually it will not open enough and can overheat on a really hot day. all this is with normal light driving under 4k rpms too.

BlueEM2

iTrader: (1)

It's a brand new thermo damnit OEM too

gearbox

iTrader: (95)

ooh hmm whats the outside temp like where you are? if its around 50F or so the lower hose may not get super hot but should still be warm. the best test is drive on the freeway for 30 mins, pull off and feel the lower hose. if its not hot, theres a problem. if the thermo is new oem (and hopefully installed the right direction), the only thing i can think of is air in the system causing it not to function properly or somethings clogged in the radiator.

Jonny2448

change the thermostat and still over heated. This time with the heater on nothing put outside temp. air cam in. I am thinking Water pump.. going to take it to the shop thanks for all the help.

BlueEM2

iTrader: (1)

Ok you need to bleed the air out of the coolant system, that's the first step when you start overheating. How is the coolant in the overflow? Click the overheating link in my signature and look at the first two posts.